1. Field of the Invention
The present invention relates to surgical repair of fractures, deformities, diseases and surgical osteotomies of bone. More particularly, the present invention relates to a method and apparatus for mandibular osteosynthesis.
2. Discussion of the Related Art
In various craniofacial surgical procedures, it is necessary to align and secure two bone portions in a relatively fixed relationship to each other. As examples, the need to establish such a secured relationship can arise from a fracture of the bone or from an oncology resection of the bone. To ensure that the bone can regenerate in the proper orientation and fuse the fracture, or maintain mandibular shape after an oncology resection, it is important that the bone portions be fixed in the desired position.
It is known in the art to provide metal plates for the repair of bone fractures. Such plates generally are secured to bone portions with fasteners, especially screws. Among other applications, such plates and fasteners are used to provide rigid stabilization of craniofacial fractures and oncology resections. The plates conventionally employed for cranial and facial osteosynthesis generally comprise small, generally flat, elongated sections of metal. The plate sections contain round and perhaps elongated screw holes at various points along their lengths for receiving screws to fasten the plate sections to bone.
Because no surface of the human skeleton is completely flat, existing plates must be extensively twisted, formed and bent during surgery to conform to portions of the skeleton on which they are to be affixed. Significant time is expended during surgery shaping and re-shaping metal plates to conform adequately to bone surfaces. This expenditure of time increases anesthesia requirements and operating room time and also increases the potential for infection.
In one commonly used technique for mandibular reconstruction, an initially flat plate is bent to conform to the contours of the surface of the mandible. The conformed plate is secured to the mandible by a plurality of screw fasteners received through holes in the plate. The screw fasteners penetrate into and gain purchase in the bone. Subsequently, the fasteners and plate are removed to allow surgical access to the mandible, e.g., to remove a cancerous growth. Finally, the plate is fastened again to the mandible by engaging the fasteners with the previously formed holes in the mandible.
While known systems utilizing plates and fasteners for cranial and facial osteosynthesis have proven to be acceptable for certain applications, such systems are nevertheless susceptible to improvements that may enhance their performance. Known systems do not provide plates having enhanced screw placement options together with enhanced bending ease at desired locations, while preserving the integrity of screw holes at bending sites and avoiding interference between screws in adjacent screw holes. These and other desirable improvements are provided by the present invention, preferred embodiments of which are described below with reference to the drawings.
According to one aspect of the present invention, an apparatus for osteosynthesis of a mandible includes an elongated plate having a plurality of apertures. The plate has a first portion and a central portion. Each of the plurality of apertures within the first portion and within the second portion is disposed in relatively close spaced relationship, and each of the plurality of apertures within the central portion is disposed in relatively widely spaced relationship.
According to another aspect of the present invention, a method of surgically repairing a mandible includes the step of providing an elongated plate having a plurality of apertures, the plate having a first portion and a central portion. Each of the plurality of apertures within the first portion is disposed in relatively close spaced relationship, and each of the plurality of apertures within the central portion is disposed in relatively widely spaced relationship. A further step includes providing a fastener having means for engaging the mandible and having means for engaging an aperture of the plate. Yet a further step includes securing the elongated plate to the mandible with the fastener. Another step includes bending the plate to substantially conform to the mandible such that the central portion overlies the symphysis of the mandible.
It is an object of the present invention to provide an osteosynthesis plate for use in surgical repair of a mandible having enhanced bending ease in the vicinity of the symphysis of the mandible.
It is a further object of the present invention to provide an osteosynthesis plate for use in surgical repair of a mandible that presents enhanced options for screw placement outside the vicinity of the symphysis of the mandible.
It is yet a further object of the present invention to provide an osteosynthesis plate for use in surgical repair of a mandible that permits bending of the plate to a relatively small radius in the vicinity of the symphysis of the mandible while preserving the boundary integrity of the apertures in the area of bending.
Additional objects and advantages of the present invention will be apparent from the descriptions below of preferred embodiments and their methods of use, made with reference to the drawings.